[TowerTalk] unguyed heights for Rohn 65 etc.?

[Jan Erik Holm]

Dont you guys ever do calculations on things like this?
A little bit of mathematics will figure all this out,
also I´m pritty sure there would be computer software
that can do stress calculations on towers depending
on how much load you put on them etc etc.
Used to do this when I was in the university, however
it was 30 years ago and darn it if I can remember how
to any more, should be able to study up on it I guess.
However these days I guess you do it in computers and
not by hand and brain.

73 Jim SM2EKM
-------------------

RICHARD BOYD wrote:
> Okay, it looks, then, as if Rohn 65 would do the job at 50' but wouldn't be 
> enough at 60' -- unguyed.  I would guess that Rohn 80 would have a little 
> more capability, being huskier.
> 
> Even putting one guy set on the tower should greatly increase its 
> capability -- I'll have to think about the aesthetic and footprint tradeoffs 
> versus the other options.
> 
> 73 - Rich, Ke3Q
> 
> 
> ----- Original Message ----- 
> From: "Joe Subich, K4IK" <k4ik at subich.com>
> To: "'RICHARD BOYD'" <ke3q at msn.com>; <towertalk at contesting.com>
> Sent: Thursday, January 13, 2005 10:59 PM
> Subject: RE: [TowerTalk] unguyed heights for Rohn 65 etc.?
> 
> 
> 
>>
>>>Anyone have an idea (or facts) how high I could go unguyed
>>>with Rohn 65, assuming a single 48' boom monobander for 20,
>>>or 15, or 10 (plus appropriate rotator, and I'll have the
>>>yagi right above the tower, shortest mast possible within
>>>reason)?
>>
>>The Rohn Commercial Catalog (11993) gives the following
>>allowable antenna areas for Rohn 65 at 80 MPH (Prince Georges
>>Co. is 75 MPH zone):
>>
>>
>>Ht.      no ice    1/2" ice
>>
>>50'       19.7       19.1
>>60'        9.4        4.1
>>
>>Note 3:  Designs assume two 7/8" lines on each tower face.
>>         (nb: 7/8" line is .0875 sq. ft. per lineal foot)
>>
>>
>>>Okay, let me toss out another possibility:  Rohn 80 (I know
>>>it comes in various sub-models, some 40" face, some 44" face
>>>and there may be other differences, but assume the basic or
>>>the typical one).
>>
>>No chart in my book for Rohn 80 free standing.  "Each tower
>>is individually engineered to handle a particular job."
>>
>>Rohn 80 is 41" center-to-center on the legs however the legs
>>vary from 2" to 3" in standard (schedule 40?) and X-STR
>>(schedule 80?).  Rohn 80 has both standard (zig-zag) and
>>cross braced sections.
>>
>>73,
>>
>>   ... Joe, K4IK
>>